This work consists of constructing and/or adjusting all new and existing utility structures encountered on the project to finished grade.
(1) Asphalt Concrete Paving. On asphalt concrete paving projects, the manholes shall not be adjusted until the final pavement is completed, at which time the center of each manhole lid shall be relocated from references previously established by the developer. The pavement shall be cut as further described and base material removed to permit removal of the cover. The manhole shall then be brought to proper grade.
Prior to commencing adjustment, a plywood and visqueen cover as approved by the district shall be placed over the manhole base and channel to protect them from debris.
The asphalt concrete pavement shall be cut and removed to a neat circle, the diameter of which shall not exceed 48 inches or 14 inches from the outside diameter of the ductile iron frame, whichever is smaller. The ductile iron frame shall be brought up to desired grade, which shall conform to surrounding road surface.
Adjustment to desired grade shall be made with the use of concrete adjustment rings or bricks. No cast or ductile iron adjustment rings will be allowed. An approved class of mortar (one part cement to two parts of plaster sand) shall be placed between adjustment rings or bricks and ductile iron frame to completely fill all voids and to provide a watertight seal. No rough or uneven surfaces will be permitted inside or out. Adjustment rings or brick shall be placed and aligned so as to provide vertical sides and vertical alignment of manhole steps and ladder. Adjustments in excess of 26 inches of depth of the 24-inch manhole neck shall require manhole section rings to raise the eccentric cone to within the adjustment ring tolerances.
Check manhole specifications for minimum and maximum manhole adjustment and step requirements. Special care shall be exercised in all operations in order not to damage the manhole, frames and lids or other existing facilities.
The annular spaces of the manhole frames shall be filled with five-eighths-inch minus crushed gravel and compacted with hand tamper to within two inches of the top of the frame. Asphalt concrete patching shall not be carried out during wet ground conditions or when air temperature is below 50 degrees F. Asphalt concrete mix shall be at required temperature when placed. Before making the asphalt concrete repair, the edges of the existing asphalt concrete pavement and the outer edge of the casting shall be tack coated with hot asphalt cement. The remaining two inches shall then be filled with HMA and compacted with hand tampers and a patching roller.
The completed patch shall match the existing paved surface for texture, density and uniformity of grade. The joint between the patch and the existing pavement shall then be carefully painted with hot asphalt cement or asphalt emulsion and shall be immediately covered with dry paving sand before asphalt cement solidifies. All debris such as asphalt pavement, cement bags, etc., shall be removed and disposed of by developer.
Prior to acceptance of a project, manholes shall be cleaned of all debris and foreign material. All manhole steps and ladders shall be cleaned free of grout. Any damage occurring to the existing facilities due to the developer’s operations shall be repaired at his own expense.
(2) Adjustment of Manholes in Easements. Manholes in easement areas shall be adjusted to ensure drainage away from the manhole frame and cover. Pour a four-foot diameter by 12-inch-thick broom finished concrete collar around the manhole frame and cover, and mark with a green carsonite marker.
(3) Adjustment of Valve Box Castings. Adjustment of valve box castings shall be made in the same manner as for manholes. [Res. 735 § 1, 2017.]